Jay Montgomery consistently had felt uncomfortable after eating meals, but he didn’t think much about the bloated feeling he nearly always experienced.

Montgomery, who owns Goldmine Jewelers in St. Charles, said it wasn’t until he had a physical exam three years ago that he discovered his diet made him feel that way.

Specifically, it was the gluten to which he was allergic. He said he didn’t realize he was living with celiac disease and a variety of common foods, including bread and pasta, had been disagreeing with his stomach.

He felt better less than a week after cutting gluten out of his diet, and now it’s a way of life.

“I felt pretty good,” he said. “I got my appetite back.”

According to the Mayo Clinic, celiac disease is a digestive condition caused by eating the protein in gluten, which is found in bread, pasta, cookies, pizza crust and other foods that contain wheat, barley or rye. The disease can cause stomach aches, diarrhea and a decreased absorption of nutrients.

The Mayo Clinic says there is no cure for the disease, but it can be managed through diet. People with celiac disease are advised to avoid a long list of foods, including croutons, pastas, bread, processed lunch meats, cookies, beer, soup, salad dressings and sauces, including soy sauce.

That can make eating out complicated, Montgomery said. If he knows he’s heading to a restaurant, he said he usually brings his own gluten-free bun so he can order a hamburger.

The growing demand for gluten-free foods didn’t escape Allen and Christina Soboj, owners of the North Island Sandwich Shoppe in Batavia.

They’ve been offering gluten-free Boars Head meats, condiments, breads and baked goods since they opened in 2011.

Allen Soboj said the popularity of gluten-free meals was highlighted a few weeks ago when a shipment of gluten-free bread didn’t come in one Saturday. He said about 10 customers walked out that day because that’s why they went there.

“There are people that specifically come here for that very reason,” he said, adding that his shop doesn’t charge extra for making a gluten-free sandwich, which he said is rare for a restaurant.

Paul Lencioni, president of Blue Goose Market, said he started adding gluten-free foods to the shelves when he began dating his wife, Melissa Sharp, six years ago. He said gluten-free products have come a long way in that period of time, improving in quality and price.

He said in the past few years, the gluten-free market has exploded.

“Gluten-free in the supermarket industry is a very well-understood category,” he said. “It’s not even emerging anymore. It’s established and continuing to go up.”

Lencioni said the rising number of gluten-free customers is on the minds of food manufacturers. Some products that always have been gluten-free now are advertised as such to capture that demographic.

Melissa Sharp said changing her diet led to drastic improvements in the way she feels. For years, she experienced stomach pain, headaches, bloating and gas – symptoms one of her friends with celiac disease also had experienced.

She said because celiac disease wasn’t as well-known as it is today, it took her a long time to determine that gluten had been the cause of her problems. In 2006, she started carefully checking food labels to avoid eating gluten, and it’s a lifestyle she maintains today.

“I could tell by the first day that I was better. Each day got progressively better,” Sharp said. “I felt really bad eating gluten and couldn’t bring myself to eat it.”